The 'diet' foods that are making you fat

'Low calorie', 'low fat', 'slimline'; are you loading up the labels but still gaining weight? We explain why these so-called weight loss foods won't help you shift the pounds - and what you should be eating to feel fit and well.

Granola snack bars

You say 'a power snack to cut down on calories'.

We say 'SUGAR'.

Most are packed with it; in fact a recent survey by Which? found that 29 out of the 30 bars sampled contained an average of 15% sugar. 15%! That's half your recommended daily amount in just a few mouthfuls. As our American friends say, 'You do the math'.

Swap it for: Beef or chicken jerky, an easy on-the-go snack that's full of flavour and packed with protein. Because high-protein foods take more work to digest and metabolise, you burn more calories as they pass through your body. And they increase the 'full feeling' by staying longer in your stomach.

In fact, in a study published in Nutrition Metabolism, dieters who increased the protein ratio in their diet to 30% ate on average 450 calories less per day and lost 11 pounds in 12 weeks.

Low calorie treats

Yes, that snack pack of biscuits claims to have less than 100 hundred calories – and no doubt it does. However, it's also packed with added sugar and that instant hit will leave you craving another, so it's a slippery slope to a calorific binge.

Sugar offers empty calories – an energy hit without any nutrients – so we merely eat more without feeling satisfied. This puts us at increased risk of weight gain and energy highs and lows, not to mention tooth decay and Type 2 diabetes.

Swap it for: A handful of almonds, as the nuts' non-fermentable fibre is great for giving that full feeling and stabilizing blood sugar levels.

A recent study in the Journal of the American Heart Association found that eating 30 to 35 almonds a day helped dieters shed abdominal fat. It's all about the fibre, which also prevents constipation and bloating.

Dried fruit

It's fruit yes, but stripped of many of the nutrients it has when fresh and often loaded with added sugar. So not only are you running foul of all of the 'sugar risks' explained above, you're also in danger of bloating. Oh yes. Dried fruit is one of the 'healthy' foods that make you bloat.

Swap it for: Well, it's not rocket science – swap it for fresh fruit! Of course fruit also contains sugar but this is naturally occurring sugar, which is VERY different to added sugar, and fruit is also a valuable source of fibre, vitamins and minerals.

But if you're being very careful, choose low sugar fruits. For example a ripe banana can have up to 21g of sugar per 100g, but apples have just over 11g, watermelons have 7g and blackberries 5g.

Fruit juice

Going for salad and a juice as a healthy, low calorie lunch? Drop the juice. As with the deadly granola bar, if you're drinking juice from concentrate, you might as well just swallow a glass of sugar. In fact, some brands are shown in tests to contain as much sugar as you would expect to find in three and a half doughnuts. No, not such a good idea for a diet…

Swap it for: A cup of green tea, packed with caffeine and antioxidants, both known to help reduce excess belly fat.

Fruit yogurt

Gone are the days you can tuck into a brightly coloured yogurt (usually in a brightly coloured pot), lapping up all that tasty syrupy 'fruit' at the bottom of the container, and think you are being virtuous.

A European Journal of Clinical Nutrition study revealed that people who drank a fermented milk beverage with probiotics every day lost a significant amount of abdominal fat. Choose products that contain 'live and active cultures' and avoid flavoured varieties to avoid the dreaded sugar.

'Healthy' ready meals

Okay, so it says 'low calorie' and 'low fat' on the packaging. But what has been added to replace the taste when everything else has been stripped out? The answer is normally sugar. And often frequently salt. Both are bad for you in excessive amounts, and may lead to food cravings where you actually end up eating more than you would have if you cooked a healthy balanced meal from scratch.

Watch out also for labels using 'reduced' fat or calorie boasts; by law this only means the product needs to have 30% fewer fat or calories. So 'reduced' doesn't necessarily mean low – and can often mean high!

And 'low sugar', 'sugar free', 'slimline' or 'diet' claims means the food probably contains artificial sweeteners, which have been linked to mood swings and depression. Research has found that people who consume them regularly tend to gain weight, as they slow down the digestive process and increase appetite.

Swap it for: A healthy, low-calorie meal; try this tasty Asian-marinated salmon with rice pilaf for a healthy option that's high on flavour.